This application is based upon and claims the benefit of priority from the prior Japanese Patent Applications No. 2000-388357, filed Dec. 21, 2000; and No. 2001-304016, filed Sep. 28, 2001, the entire contents of both of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a substrate processing apparatus and a substrate processing method for use in the steps of manufacturing semiconductor devices, photomasks, liquid crystal displays, etc. The present invention particularly relates to a developing apparatus and a developing method by use of the developing apparatus for developing a substrate coated with a photoresist and exposed to light via a predetermined pattern.
2. Description of the Related Art
In the steps of manufacturing semiconductor devices and liquid crystal displays, a photoetching process is repeatedly applied to a substrate. In the photoetching process, a photoresist is applied to a substrate, and the photoresist-coated substrate is exposed to light via a predetermined pattern. The pattern-exposed substrate is developed by a developing solution in a developing apparatus to thereby remove the photoresist of, for example, the parts exposed to light.
In the developing step thus performed, a dip method in which a substrate is treated while being immersed in a developing solution, a spray method in which a substrate is treated by spraying a developing solution on the surface to be treated (hereinafter, sometimes referred to as a xe2x80x9ctreatment-receipt surfacexe2x80x9d), and a paddle method in which a substrate is treated by supplying a developing solution to the treatment-receipt surface while rotating.
However, the dip method and the spray method have problems. They require a large amount of developing solution and much cost for treating waster water. Therefore, they have been replaced by the paddle method. The paddle method, however, has a problem of nonuniform development. This is because the discharge pressure and the supply amount of the developing solution per unit area differ between the center of the substrate and the periphery.
Under the circumstances, a scan method as shown in Japanese Patent Application No. 7-36195 (hereinafter, referred to as xe2x80x9cPrior Artxe2x80x9d) has hitherto been developed. In the scan method, a developing solution is supplied to the treatment-receipt surface by moving a nozzle supplying the developing solution in a scanning manner, and then, developing is performed by the developing solution supplied onto the substrate.
Recently, in the field of semiconductors, with the progress of miniaturization and high integration of semiconductor devices, the demand for miniaturizing semiconductor devices in the photoetching step has increased. At present, the design rule of devices has reached a level of 0.13 xcexcm. The dimensions of a pattern are required to be controlled with an extremely high accuracy of about 10 nm.
However, the conventional scan-development mentioned above is accompanied by such a problem that the pattern size finally obtained differs from the predetermined pattern size due to uneven density of the pattern. More specifically, in the conventional scan-development, although a developing solution is supplied to the treatment-receipt surface of a substrate in a scanning manner, the developing solution supplied to the substrate as a liquid-mountain (globule) is rarely replaced with a fresh one. Therefore, the amount of the product resulting from the developing solution reacting with the resist differs between a densely patterned portion and a non-densely patterned portion, with the result that the concentration of the developing solution differs between both portions. Due to the uneven density of the pattern, a pattern cannot be obtained with high accuracy.
As described above, the developing solution supplied onto the treatment-receipt surface is rarely replaced in conventional scan development. Because of this, particularly in the case of a pattern with an uneven density, the concentration of the developing solution locally changes during the developing process. As a result, the pattern size varies depending upon the uneven density of the pattern. Hence, the pattern cannot be obtained with high accuracy.
According to an aspect of the present invention, there is provided an apparatus for processing a substrate comprising
a substrate holding mechanism for holding the substrate substantially horizontally;
a chemical solution discharge/suction mechanism having a chemical solution discharge/suction portion which has a chemical solution outlet for discharging a chemical solution onto the substrate and chemical solution inlets for sucking up the chemical solution present on the substrate; and
a chemical solution supply/suction system for supplying the chemical solution to the chemical solution discharge/suction mechanism simultaneously with sucking the chemical solution by the chemical solution supply/suction mechanism.
According to another aspect of the present invention, there is provided an apparatus for processing a substrate comprising:
a substrate holding mechanism for holding the substrate substantially horizontally;
a chemical solution discharge/suction mechanism having a chemical solution discharge/suction portion in which at least two chemical solution outlets for discharging a chemical solution onto the substrate and at least two chemical solution inlets for sucking up the chemical solution present on the substrate are arranged alternately; and
a chemical solution supply/suction system for supplying the chemical solution to the chemical solution discharge/suction mechanism simultaneously with sucking the chemical solution by the chemical solution supply/suction mechanism.
According to another aspect of the present invention, there is provided a substrate processing method for processing a surface of a substrate with a chemical solution comprising:
discharging the chemical solution onto the substrate whose surface to be treated is horizontally held, continuously through a chemical solution outlet of a chemical solution discharge/suction portion; and
simultaneously sucking up the chemical solution on the surface to be treated continuously through a chemical solution inlet arranged next to the chemical solution outlet in the chemical solution discharge/suction portion, while the chemical solution discharge/suction portion is horizontally moved relative to the substrate,
in which a fresh chemical solution is always supplied to a gap between the chemical solution discharge/suction portion and the substrate and in the region between the chemical solution outlet and the chemical solution inlet.
According to another aspect of the present invention, there is provided a substrate processing method for processing a surface of a substrate to be treated with a chemical solution comprising:
arranging a chemical solution discharge/suction portion having at least two chemical solution outlets for discharging the chemical solution and at least two chemical solution inlets alternately arranged, on the substrate whose surface to be treated is held substantially horizontally;
discharging the chemical solution continuously onto the substrate to be treated from the chemical solution outlets; and
simultaneously sucking up the chemical solution on the surface to be treated continuously through the chemical solution inlets, while horizontally moving the chemical solution discharge/suction portion relative to the substrate, thereby treating the surface to be treated with the chemical solution,
in which a fresh chemical solution is always supplied to a gap between the chemical solution discharge/suction portion and the substrate and in the region between each of the chemical solution outlets and each of the chemical solution inlets.